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tdoa3 random send, packet will conflict， PTP(Precision Time Protocol) can solve it
Posted: Fri Jun 14, 2019 4:04 am
by justinleeyang
hi,
tdoa3 random send, packet will conflict，I think that PTP(Precision Time Protocol) can solve it.
PTP can sync all anchor time, then every anchor run tdma mechanism to avoid collision。
Re: tdoa3 random send, packet will conflict， PTP(Precision Time Protocol) can solve it
Posted: Mon Jun 17, 2019 6:49 am
by arnaud
TDoA2 is synchronizing all anchors and using TDMA. The problem with the TDMA approach is that it does not scale that well.
First of all, in TDoA2 we use anchor 0 as a master clock for TDMA, this means that losing anchor 0 stops the system. Having a more distributed approach for time-keeping would solve this problem. If you have an idea about such an algorithm that would be great. Raw PTP assumes one source for the clock as far as I understand so it would not solve this problem.
The main problem is a scalability one: we need to assign one TDMA slot per anchor. This is great in a small system when all anchors sees each-others. When the system becomes bigger we either slow down the system very much by not re-using time-slot and having a lot of timestots or we risk collision by re-using time-slots for anchors that might have an overlapping coverage. Overall it seems that handling such a system will become very complex and hard to setup.